In an exemplary briefcase embodiment as depicted in FIG. A stack of alternating, substantially tubular electrically insulating fluid seals and header connector elements is assembled in axial alignment to form a common, elongated axial stack bore sized in diameter and length to receive the lead connector assembly. The protection setting determiner uses the physical parameters to update the protection settings. As the circuit cards are inserted into or disconnected from an electronic system, coolant communication is enabled or disabled, respectively between one or more heat exchange units and the heat transfer units disposed on the circuit card at the time electrical connection of the circuit card is established or disconnected, respectively.